1. Field of the Invention
This invention relates to a protecting element and especially relates to a protecting element that significantly improves the electrostatic breakdown voltage without degrading the high-frequency characteristics of a protected element.
2. Description of the Related Art
FIG. 11 show equivalent circuit diagrams of semiconductor devices with junctions or capacitors.
FIG. 11A is an equivalent circuit diagram of a GaAs MESFET, FIG. 11B is that of a bipolar transistor, and FIG. 11C is that of a MOSFET.
As shown by these diagrams, in considering the electrostatic breakdown voltage, any semiconductor device may be expressed as an equivalent circuit composed of diodes, capacitors, and resistors (inductors may be included in the case of a high-frequency device).
Also, a diode may express a PN junction or a Schottky junction. For example, the diodes of a GaAs MESFET are Schottky barrier diodes and the diodes of a bipolar transistor are PN junction diodes.
Generally with related-art semiconductor devices, the method of connecting an electrostatic breakdown protecting diode in parallel to a device containing a PN junction, Schottky junction, or capacitor that is easily damaged by electrostatic discharge may be considered for protection of the device from static electricity.